Analysis It's going to be a tough task securing the Internet of Things, an upcoming massive global network of web-connected fridges, freezers and pacemakers. But according to experts gathered in Cambridge last week we can't even start locking it down until we know who's going to make money from it.

The meeting was run by Cambridge Wireless, and attended by luminaries from all the important companies hoping to cash in on the Internet of Things. They came to hear talks from chip designers CSR and Nordic Semiconductor, and the usual round of consultants. The confab focussed on how 50 billion devices could be wired up to the public internet by 2020 and how they will be protected from the legions of ne'er-do-wells poised to hijack light switches and washing machines around the world.

At a basic level, securing those devices will involve cryptographic keys and authentication mechanisms, such as those made by Nordic Semiconductor which explained how its own embedded security had evolved.

But security is more than cryptography; equally important are architectures capable of distributing data while maintaining the owner's control over the distribution, and ensuring services aren't locked to suppliers, all of which will depend almost entirely on how companies decide to make money from the idea.

Millions and millions of things talking to each other without a business model between them

If one accepts that 50 billion devices are going to be connected, and that a significant proportion of those devices are going to be in our homes (as opposed to traffic lights, parking meters or cow bells) then we need to establish if those light switches and smart fridges are going to connect straight back to their preferred cloud or whether the data will be aggregated at a home hub.

The former is simpler, but the latter permits analysis by the residents, who will be able to decide which streams of information are passed to which services, and may be legally mandated across the European Union at least. This will be in a world in which light bulbs report that they've been left on all night to power giants, and fridges let your supermarket's warehouse nightshift know when you're about to run out of chocolate body spread.

Liz Fitzsimons of "legal innovators" Eversheds explained the legal responsibilities involved. The latest European privacy directives may require that sensors around our homes ask our permission before phoning home, not only to prevent illicit data gathering but also allowing us to take our data elsewhere if we sign with another provider - redirecting the readings from our smart electricity meter to a company that won't switch it off in the middle of EastEnders, for example.

Those controls would probably fall to the home hub, but there aren't any standards by which such a device could operate so one could end up locked to a proprietary hub instead of a service.

There's a comparison to apps here, though not enough to justify the term "appcessories" which was banded about Internet of Things celebrity Nick Hunn. A smartphone can have dozens of applications installed, most of which have the authority to contact a cloud whenever they want to share data of all sorts. Users seem quite comfortable with that, but regulators are becoming more interested and when the same things starts happening with hardware it becomes more of an issue.

Those regulators are ready to fight too; updates to EU law will allow states to fine a company up to two per cent of its global revenue if it's caught slurping data without permission.

Hunn pointed out that even a smart meter of limited intelligence can identify larger household appliances, such as an electric shower, while a water meter can tell you if anyone's home with some accuracy - so security of that data is important. Determined and suitably tooled-up eavesdropping burglars will be lured to properties that advertise themselves as temporarily unoccupied.

Current thinking is that cryptographic keys distributed by the supplier will secure the data end-to-end, but that would mean an irritating change of meter with every change of supplier at a time when customer choice is supposed to be paramount.

Smart meters are supposed to make changing suppliers easier. The enormous cost is, in part, justified by their ability to drive down prices by increasing competition.